chore(deps): update ghcr.io/rails/devcontainer/images/ruby docker tag to v3.4.8

[renovate]

This PR contains the following updates:

Package	Type	Update	Change
ghcr.io/rails/devcontainer/images/ruby	final	patch	3.4.2 -> 3.4.8

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.00%. Comparing base (3d58786) to head (15cb346).
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@            Coverage Diff            @@
##            master      #507   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files          109       109           
  Lines         2359      2359           
  Branches        72        72           
=========================================
  Hits          2359      2359           

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